For the therapeutic treatment, in particular of the gastric mucosa, for example for tumor resection or also for changing the eating and weight behavior of patients, the large-area ablation and/or coagulation of sharply defined areas of the mucosa and the submucosa may be necessary, in which case the coagulation depth in the treated area should be as uniform as possible, so that the muscularis is not destroyed. Typically, therapeutic mucosal ablation is performed by means of an endoscope, wherein special probes can be used for ablation.
For example, document WO 2011/022069 A discloses an endoscope with an end cap that is to be placed on the mucosa, and an argon plasma coagulation is performed on its inside. The cap is to limit the effective region of the argon plasma coagulation.
Document U.S. Pat. No. 8,641,711 B2 describes an instrument for the ablation of tissue layers of hollow organs, wherein the instrument comprises an electrically active head with electrodes. The head is provided with an expandable element for positioning the head relative to the oppositely located tissue wall in a defined manner.
Document US 2004/0215180 A1 discloses an ablation probe with several wire-like individual electrodes projecting from the distal end of the probe, said electrodes being connected together to an electrical conductor and being supplied via the latter with electrical current from an electrical power generator, said electrical current effecting the ablation.
Document US 2003/0181900 A1 illustrates a probe for contact-coagulation with the use of several electrodes that—during operation resting against the tissue—are connected chronologically in sequence to an HF generator consistent with a specific schematic diagram.
For the simultaneous surgical treatment of biological tissue with the use of several plasma spark probes, document DE 10 2005 007 769 A1 describes a system comprising several monopolar instruments that are connected to a single HF generator via a high-voltage switch, in which case the switches are closed alternately, so that the individual instruments receive HF current intermittently.